JP3159347B2 - IC test equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IC test apparatus capable of accurately testing a device under test.

[0002]

2. Description of the Related Art An IC test apparatus adds an analog signal to test an IC of a device under test (hereinafter abbreviated as a DUT) having an analog signal processing unit, measures an analog signal output from the DUT, and measures the DUT. Perform a functional test.
When the analog signal output to the DUT has a high frequency, the amount of attenuation of the analog signal becomes a problem due to the passing electronic elements and the transmission path length. In other words, even if it is intended to generate an analog signal from the signal generator and add a desired analog signal to the DUT, the signal is attenuated by the transmission path length to the DUT and the electronic elements, so that the signal is actually added to the DUT. Analog signals are attenuated. Similarly, D
Even if an analog signal is output from the UT, the signal is attenuated by a measuring instrument that measures the analog signal. Therefore, even if the DUT is non-defective, a normal signal is not output from the DUT due to attenuation of the analog signal, and the DUT is erroneously determined to be defective. Therefore, it is necessary to adjust the amplitude of the analog signal.

FIG. 3 shows a configuration diagram of an IC test apparatus. In FIG. 1, reference numeral 1 denotes a main body, which includes a control unit for controlling the apparatus, a measurement module 2, and the like. The measurement module 2 is a signal generator that outputs an analog signal, a measuring device that measures an analog signal, or the like. A test head 3 is connected to the main body 1. 4 is a performance board, test head 3
, And the test head 3 and the DUT 6 are connected. Then, the measurement module 2 is connected to the coaxial cable 8 in the test head 3 via the coaxial cable 7. Further, the coaxial cable 8 is connected to the spring contact pin 5.

[0004]

Normally, the calibration of the measurement module 2 is performed only for the coaxial cable 7.
That is, when an analog signal is generated, the signal output from the measurement module 2 via the coaxial cable 7 is D
Calibration is performed so that a signal to be actually output to the input terminal of the UT 6 is obtained. When measuring an analog signal, the signal input to the measurement module 2 via the coaxial cable 7 is calibrated so that the amplitude level of the signal input from the coaxial cable 8 to the coaxial cable 7 becomes the same as the measurement result. I do.
However, in the actual measurement of the DUT 6, there is a problem that the attenuation of the coaxial cable 8 and the spring contact pin 5 in the test head 3 causes an error.

An object of the present invention is to realize an IC test apparatus capable of accurately testing a device under test by grasping the amount of analog signal attenuation in a test head.

[0006]

SUMMARY OF THE INVENTION The present invention relates to an IC test apparatus for inputting or outputting an analog signal to a device under test via a test head and testing the device under test. A storage unit that stores a signal attenuation amount for each frequency, and a control unit that adjusts the amplitude of an analog signal according to the frequency based on the attenuation amount of the storage unit. It is.

[0007]

According to the present invention, the control section corrects the amplitude of the analog signal based on the amount of attenuation by the test head in the storage section.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is a configuration diagram showing one embodiment of the present invention. In the figure,
9 is a test system controller (hereinafter abbreviated as TSC)
And controls the overall control of the device. 10 and 11 are module controllers (hereinafter abbreviated as MC) connected to the TSC 9
This controls the measurement module. Reference numeral 12 denotes a signal generator which is a measurement module, which is controlled by the MC 10 and generates an analog signal. Reference numeral 13 denotes a signal measuring device which is a measuring module, which is controlled by the MC 11 to measure an analog signal. 1
Reference numerals 4 and 15 denote coaxial cables, which are signal generators 12 and 15, respectively.
Connected to signal measuring device 13. 16 is a test head,
A signal generator 12 or a signal measuring device 13 is connected via coaxial cables 14 and 15, respectively. The test head 16 is connected to the TSC 9. Reference numeral 17 denotes a measurement board having a connector 18, which is connected to the test head 16 when measuring the amount of attenuation of the test head 16. 19
Is a performance board, which is connected to the test head 16 when testing the DUT 20. Reference numeral 21 denotes a memory for storing a measurement result of the signal measuring device 13.

In the test head 16, reference numeral 22 denotes a panel of the test head 16, which is provided with connectors 23 and 24 for connecting coaxial cables. The connector 23 and the connector 24 are connected to each other. Reference numeral 25 denotes a coaxial cable which is connected to the connector 24 and connected to the spring contact pin 26. And spring contact pin 2
6 is a measurement board 17 or a performance board 19
Connect to Reference numeral 27 denotes a memory as a storage unit, which stores the attenuation amount of the test head 16, that is, the frequency at which the attenuation amount of the analog signal in the coaxial cable 25 and the spring contact pin 26 is handled. Here, based on the attenuation amount of the memory 27, the control units that adjust according to the frequency at which the amplitude of the analog signal is handled are the TSC9, the MC10, and the MC11.
Further, the description will be made on the assumption that the signal is not attenuated in the connectors 18, 23, 24 and the panel 22.

The operation of such a device will be described below.
First, an operation for obtaining the attenuation of the test head 16 will be described.
First, the coaxial cable 14 is connected to the connector 23, and the coaxial cable 15 is connected to the connector 24. And T
The SC 9 causes the signal generator 12 to output a sine wave having a constant period via the MC 10. The TSC 9 is connected to the signal measuring device 13 via the MC 11 by the coaxial cable 14 and the connector 2.
3, 24, coaxial cable 15 and passed signal generator 12
Measure the signal from The TSC 9 calculates the amount of attenuation based on the measurement result of the signal measuring device 13 and stores it in the memory 21. Then, the TSC 9 performs the above operation for the sine waves of different frequencies, obtains the amount of attenuation, and stores the amount of attenuation corresponding to each frequency in the memory 21.

Next, a measuring board 17 is attached to the test head 16.
Connect. Then, the coaxial cable 25 is connected to the connector 24.
And the coaxial cable 15 is connected to the connector 18 of the measurement board 17. Then, the TSC 9 causes the signal generator 12 to output a sine wave having a constant period via the MC 10.
The TSC 9 is connected to the signal measuring device 13 via the MC 11 by the coaxial cable 14, the connectors 23 and 24, the coaxial cable 25, the spring contact pin 26, the connector 18,
The signal from the signal generator 12 passing through the coaxial cable 15 is measured. The TSC 9 calculates the amount of attenuation based on the measurement result of the signal measuring device 13 and stores it in the memory 21. And TS
C9 performs the above operation for sine waves of different frequencies, obtains the amount of attenuation, and stores the amount of attenuation corresponding to each frequency in the memory 21.

The TSC 9 obtains the amount of attenuation of the test head 16 from the amount of attenuation when the coaxial cable 15 is connected to the connector 24 and the amount of attenuation when the coaxial cable 15 is connected to the connector 18. 27
To be stored.

Next, how to determine the amount of attenuation of the test head 16 will be described with a specific example. FIG. 2 shows the memory 2 of the device of FIG.
It is a figure showing the example of data stored in 1 and 27. In the figure, the frequency is the frequency of the sine wave output from the signal generator 12, and the attenuation of the coaxial cable 14 and the attenuation of the device are data stored in the memory 21. The attenuation of the test head 16 is data stored in the memory 27 of the test head 16. For example, a case where the frequency of the sine wave generated by the signal generator 12 is 10 MHz will be described. At this time, when the coaxial cable 15 is connected to the connector 24, that is, the attenuation of the coaxial cable 14 is −0.0.
6 dBm. When the coaxial cable 15 is connected to the connector 18, that is, the attenuation of the device is -1.6.
dBm. The TSC 9 retrieves the data from the memory 21 and obtains the attenuation of the test head 16. The attenuation of the test head 16 is (attenuation of the device)-(attenuation of the coaxial cable 14). That is,
The attenuation of the test head 16 is -1.6-(-0.6)
= −1.0 dBm. This is stored in the memory 27 in the test head 16.

The operation of testing the DUT 20 will be described below. The measurement board 17 is removed, and the performance board 19 is connected to the test head 16. TSC9 is D
The amount of attenuation corresponding to the frequency of the signal applied to the UT 20 is extracted from the memory 27, and a correction value of the signal is obtained. Then, the corrected analog signal is output to the signal generator 12 via the MC 10. That is, at 10 MHz, -5d
When an analog signal having an amplitude of Bm is applied to the DUT 20, (amplitude applied to the DUT 20)-(test head 16
−5 − (− 1.0) = − 4 dB
m. At this level, the TSC 9 causes the signal generator 12 to output an analog signal via the MC 10. Then, the analog signal is attenuated by the test head 16 and a signal of −5 dBm is input to the input terminal of the DUT 20.

In measuring the analog signal output from the DUT 20, the TSC 9 extracts from the memory 27 the amount of attenuation of the frequency output from the DUT 20. And TS
C9 corrects the amount of attenuation with respect to the result of the signal measuring device 13 measuring the signal from the DUT 20.

As described above, since the amount of attenuation of the test head 16 corresponding to the frequency of the analog signal is taken out from the memory 27 in the test head 16 and the analog signal is corrected, an accurate test can be performed.

[0017]

According to the present invention, since a storage unit is provided for storing the amount of attenuation of the test head for each frequency used, the analog signal can be corrected and an accurate test can be performed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention.

FIG. 2 is a diagram showing an example of data stored in memories 21 and 27 of the apparatus of FIG.

FIG. 3 is a configuration diagram of an IC test apparatus.

[Explanation of symbols]

 9 TSC 10, 11 MC 16 Test head 20 DUT 27 Memory

Claims (1)

(57) [Claims] 1. An IC test apparatus for inputting or outputting an analog signal to a device under test via a test head and performing a test on the device under test. An IC test apparatus comprising: a storage unit configured to store an analog signal; and a control unit that adjusts the amplitude of an analog signal in accordance with a frequency based on the attenuation amount of the storage unit.